1. Field of the Invention
The present invention relates to an image processing apparatus and method and, more particularly, to an image processing apparatus and method for reproducing at least an image from a digital data sequence such as a Motion Picture Experts Group layer 2 (MPEG2) datastream.
2. Description of Related Art
In recent years, digital television broadcast using a satellite broadcast or cable broadcast system has been started. Upon implementation of digital broadcast, many effects such as improvement of qualities of image and sound data including audio data, increases in the number of kinds and volume of programs exploiting various compression techniques, provision of new services such as an interactive service and the like, advance of the receiving pattern, and the like, are expected.
FIG. 1 is a block diagram showing the arrangement of a digital broadcast receiver 10 using satellite broadcast.
A television (TV) broadcast wave transmitted from a broadcast satellite is received by an antenna 1. The received TV broadcast wave is tuned by a tuner 2 to demodulate TV information. After that, an error correction process, and a charging process, descramble process, and the like if necessary are done, although not shown. Various data multiplexed as the TV information are demultiplexed by a multiplexed signal demultiplexer 3. The TV information is demultiplexed into image information, sound information, and other additional data. The demultiplexed data are decoded by a decoder 4. Of the decoded data, image information and sound information are converted into analog data by a D/A converter 5, and these data are reproduced by a television receiver (TV) 6. On the other hand, the additional data has a role of program sub-data, and is associated with various functions.
Furthermore, a VTR 7 is used to record/reproduce the received TV information. The receiver 10 and VTR 7 are connected via a digital data interface such as IEEE 1394 or the like. The VTR 7 has a recording format such as a digital recording system, and records TV information as bitstream data based on, e.g., D-VHS. Note that TV information of digital TV broadcast can be recorded not only by bitstream recording based on D-VHS, but also by the digital Video (DV) format as another home-use digital recording scheme, or digital recording apparatuses using various disk media. In such case, format conversion may often be required.
The aforementioned digital TV broadcast and digital recording apparatus mainly adopt a data format encoded by MPEG2.
However, in order to display a TV program table on the TV 6 in ground wave broadcast or the aforementioned digital TV broadcast, only a method of simply displaying a main image sent from a broadcast station is available. Teletext is known as an example for displaying sub information appended to the main image. However, teletext can provide limited information such as text information or the like, and cannot handle any image.
A TV receiver that displays a plurality of channels of images on multi-windows is available. However, the individual images are sent as a main image with a large information size.
Upon implementing multi-functional TV broadcast or the like, it is desired to obtain information that pertains to a main image or that the user wants occasionally, if it does not pertain to the main image, in the form of an image (which may include sound data) as sub data with a small information size which is appended to the main image. However, such technique is not realized yet.
The present invention has been made to solve the aforementioned problems and to provide a function of reproducing information which pertains to a main image or which is desired occasionally, even if it does not pertain to the main image, at least in the form of an image.
In order to achieve the above object, a preferred embodiment of the present invention discloses an image processing apparatus comprising inputting means for inputting a data stream of MPEG 2; detecting means for detecting a data stream of MPEG 4 inserted into the data stream of MPEG 2; separating means for separating the data stream of MPEG2 and/or the data stream of MPEG 4 to a plurality of data; decoding means for decoding the separated data; and controlling means for controlling at least reproduction of image data decoded by said decoding means based on a result of said detecting means.
Also, a preferred embodiment of the present invention discloses an image processing method comprising the steps of inputting a data stream of MPEG 2; detecting a data stream of MPEG 4 inserted into the data stream of MPEG 2; separating the data stream of MPEG2 and/or the data stream of MPEG 4 to a plurality of data; decoding the separated data; and controlling at least reproduction of image data decoded by said decoding means based on a result of the detection.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.